A letter of 1792 unquestionably witnesses that Brother Antonio Maria Baroffio stored the “Trasparenti” (probably the first “doors” that had yet to be completed) in the rooms of the convent of the Servants of Mary by the Church of St. John, and we can say that at least these have always remained there since then.
We presume that the ones related to the convent and to the church were also stored there, and perhaps even all the lamps of Good Friday's procession. They were initially at most about twenty, precisely the ones that accompanied the statues of the Blessed Virgin and of the dead Christ.
The “Trasparenti” of Mendrisio were produced with a technique and with materials that had no equal in the framework of the “classical” painting on canvas.
With the due variants, we can say that, in a broad sense, these paintings were produced on fine but compact canvases made translucent by impregnating them with waxes and/or oily-resinous substances. Moreover, these substances make the canvases water resistant, thus allowing their exposure outdoors.
The painting was traditionally executed with drying oil (walnut or linseed) by exploiting the characteristics of either transparency or opaqueness of each pigment.
Despite the amazing resistance to degradation shown by these paintings, it is normal for various types of damages to occur during installation or exhibition phases; hence, we can imagine that maintenance interventions were performed immediately and often by totally inexperienced people.